WO2012137528A1 - Pneumatic tire, and method for manufacturing same - Google Patents
Pneumatic tire, and method for manufacturing same Download PDFInfo
- Publication number
- WO2012137528A1 WO2012137528A1 PCT/JP2012/051998 JP2012051998W WO2012137528A1 WO 2012137528 A1 WO2012137528 A1 WO 2012137528A1 JP 2012051998 W JP2012051998 W JP 2012051998W WO 2012137528 A1 WO2012137528 A1 WO 2012137528A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- core
- bead
- wire
- tire
- sheath
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims abstract description 18
- 238000004519 manufacturing process Methods 0.000 title claims description 10
- 239000011324 bead Substances 0.000 claims abstract description 99
- 229920001971 elastomer Polymers 0.000 claims description 27
- 239000005060 rubber Substances 0.000 claims description 27
- 238000004804 winding Methods 0.000 claims description 7
- 229910000831 Steel Inorganic materials 0.000 claims description 6
- 239000010959 steel Substances 0.000 claims description 6
- 238000000465 moulding Methods 0.000 claims description 2
- 238000005260 corrosion Methods 0.000 abstract description 5
- 230000007797 corrosion Effects 0.000 abstract description 5
- 206010028347 Muscle twitching Diseases 0.000 abstract 1
- 230000035699 permeability Effects 0.000 description 13
- 230000015572 biosynthetic process Effects 0.000 description 5
- 238000010276 construction Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 230000002411 adverse Effects 0.000 description 3
- 239000000835 fiber Substances 0.000 description 3
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 3
- 238000005452 bending Methods 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000035515 penetration Effects 0.000 description 2
- 229920000139 polyethylene terephthalate Polymers 0.000 description 2
- 239000005020 polyethylene terephthalate Substances 0.000 description 2
- 241000254043 Melolonthinae Species 0.000 description 1
- 239000004677 Nylon Substances 0.000 description 1
- 239000004760 aramid Substances 0.000 description 1
- 229920003235 aromatic polyamide Polymers 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000004049 embossing Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 239000011112 polyethylene naphthalate Substances 0.000 description 1
- -1 polyethylene terephthalate Polymers 0.000 description 1
- 230000001953 sensory effect Effects 0.000 description 1
- 238000009864 tensile test Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 238000004073 vulcanization Methods 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C15/00—Tyre beads, e.g. ply turn-up or overlap
- B60C15/04—Bead cores
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D30/00—Producing pneumatic or solid tyres or parts thereof
- B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
- B29D30/08—Building tyres
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D30/00—Producing pneumatic or solid tyres or parts thereof
- B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
- B29D30/48—Bead-rings or bead-cores; Treatment thereof prior to building the tyre
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C15/00—Tyre beads, e.g. ply turn-up or overlap
- B60C15/0009—Tyre beads, e.g. ply turn-up or overlap features of the carcass terminal portion
- B60C15/0018—Tyre beads, e.g. ply turn-up or overlap features of the carcass terminal portion not folded around the bead core, e.g. floating or down ply
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
- B60C9/0057—Reinforcements comprising preshaped elements, e.g. undulated or zig-zag filaments
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B1/00—Constructional features of ropes or cables
- D07B1/06—Ropes or cables built-up from metal wires, e.g. of section wires around a hemp core
- D07B1/0606—Reinforcing cords for rubber or plastic articles
- D07B1/0646—Reinforcing cords for rubber or plastic articles comprising longitudinally preformed wires
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B1/00—Constructional features of ropes or cables
- D07B1/06—Ropes or cables built-up from metal wires, e.g. of section wires around a hemp core
- D07B1/0606—Reinforcing cords for rubber or plastic articles
- D07B1/0646—Reinforcing cords for rubber or plastic articles comprising longitudinally preformed wires
- D07B1/0653—Reinforcing cords for rubber or plastic articles comprising longitudinally preformed wires in the core
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D30/00—Producing pneumatic or solid tyres or parts thereof
- B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
- B29D30/48—Bead-rings or bead-cores; Treatment thereof prior to building the tyre
- B29D2030/485—Bead-rings or bead-cores; Treatment thereof prior to building the tyre the bead cores being made using a band containing a plurality of wires embedded in rubber
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2201/00—Ropes or cables
- D07B2201/20—Rope or cable components
- D07B2201/2015—Strands
- D07B2201/2024—Strands twisted
- D07B2201/2027—Compact winding
- D07B2201/2028—Compact winding having the same lay direction and lay pitch
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2201/00—Ropes or cables
- D07B2201/20—Rope or cable components
- D07B2201/2047—Cores
- D07B2201/2052—Cores characterised by their structure
- D07B2201/2059—Cores characterised by their structure comprising wires
- D07B2201/2061—Cores characterised by their structure comprising wires resulting in a twisted structure
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2207/00—Rope or cable making machines
- D07B2207/20—Type of machine
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2501/00—Application field
- D07B2501/20—Application field related to ropes or cables
- D07B2501/2046—Tire cords
- D07B2501/2053—Tire cords for wheel rim attachment
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T152/00—Resilient tires and wheels
- Y10T152/10—Tires, resilient
- Y10T152/10495—Pneumatic tire or inner tube
- Y10T152/10819—Characterized by the structure of the bead portion of the tire
Definitions
- the present invention relates to a pneumatic tire having a bead structure in which a radially inner end portion of a carcass ply is sandwiched between core pieces inside and outside in the tire axial direction, and a manufacturing method thereof.
- a rigid core a having an outer surface shape corresponding to the tire inner surface shape of the vulcanized tire is used.
- a tire component such as an inner liner, carcass ply, bead core, belt ply, sidewall rubber, and tread rubber is sequentially attached to form an unvulcanized tire t, and this unvulcanized tire t is added together with a rigid core a.
- a construction method in which a tire is vulcanized and molded between a rigid core a as an inner mold and a vulcanization mold b as an outer mold hereinafter sometimes referred to as a core construction method).
- a core construction method has been proposed.
- the radial height of the bead core d can be maximized within a limited number of turns of the bead wire e, the contact area with the carcass ply is increased, and the locking force to both ends of the carcass ply is secured. can do.
- the present invention is based on adopting a predetermined twisted structure using a plurality of steel strands instead of a single wire as a bead wire, while ensuring corrosion resistance and air leak resistance, It is an object of the present invention to provide a pneumatic tire capable of preventing the core deformation during assembling of the rim by imparting moderate flexibility to the tire, and a method for manufacturing the same.
- the invention of claim 1 of the present application is a pneumatic tire comprising a carcass made of a carcass ply extending from a tread portion to a bead core of a bead portion through a sidewall portion,
- the bead core is composed of inner and outer core pieces in the tire axial direction, and the radially inner end portion of the carcass ply is sandwiched between the inner and outer core pieces without being folded around the bead core,
- the inner and outer core pieces are spirally wound with a bead wire formed by twisting together a plurality of steel strands having the same wire diameter from the inside in the radial direction to the outside to the height position beyond the radially outer end of the rim flange.
- the bead wire includes a core portion obtained by twisting two or more core strands and a sheath portion obtained by twisting three or more sheath strands around the core portion, and the core strand and / or
- the sheath wire includes a shaped wire that is shaped in a spiral or wave shape before being twisted, and The twist direction and twist pitch Pc of the core strand are the same as the twist direction and twist pitch Ps of the sheath strand.
- the invention of claim 3 is a method for producing a pneumatic tire comprising a carcass made of a carcass ply extending from a tread portion through a sidewall portion to a bead core of the bead portion, Using a rigid core provided with a tire forming surface that forms the inner cavity surface of a pneumatic tire on the outer surface, unvulcanized tire components including a bead core and a carcass ply are sequentially pasted on the tire forming surface.
- a rubber-coated bead wire coated with unvulcanized rubber is spirally wound from the inside in the radial direction to the outside on the tire forming surface to form an inner core piece.
- a first core piece process A carcass forming step having a step of sticking a radially inner end portion of the carcass ply to the outer side in the tire axial direction of the inner core piece; A second core piece step of forming an outer core piece by winding and sticking the rubberized bead wire on the outer side in the tire axial direction of the radially inner end of the carcass ply in a spiral shape from the inner side to the outer side in the radial direction
- the bead wire includes a core portion obtained by twisting two or more core strands and a sheath portion obtained by twisting three or more sheath strands around the core portion, and the core strand and / or
- the sheath wire includes a shaped wire that is shaped in a spiral or wave shape before being twisted, and The twist direction and twist pitch Pc of the core strand are the same as the twist direction and twist pitch Ps of the sheath strand.
- the bead wire includes a core portion obtained by twisting core strands and a sheath portion obtained by twisting sheath strands around the core portion, and the twist direction and twist pitch Pc of the core strands are A twist structure that is the same as the twist direction and the twist pitch Ps of the sheath wire is employed.
- the core strand and the sheath strand have the same twisting direction and twisting pitch, the strands are the most compact in the same manner as a so-called bundle twist structure in which a plurality of strands are bundled and twisted together. Can be twisted together. Therefore, the formation of a space in the wire is reduced, deformation in the direction in which the wire cross-sectional shape changes can be kept low, and the fitting force with the rim can be increased to maintain steering stability. In the case of a normal layer twist structure in which at least one of the twist direction or the twist pitch is different, a space for the sheath wire to fall in the core portion is formed, so that the fitting force with the rim is reduced and the steering stability is adversely affected. give.
- the position of the strands is randomly changed in the wire, so that the cross-sectional shape is not uniform in the circumferential direction. Therefore, in the circumferential direction, there is a tendency that a place where the fitting pressure with the rim is strong and a weak place are formed, and the air leakage resistance is deteriorated such that the filling air easily leaks from the place where the fitting pressure is weak.
- the position of the strand does not change and the cross-sectional shape is stable in the circumferential direction, so that the air leak resistance can be kept high.
- the bead wire includes the embossed element wire
- the rubber penetration into the wire can be improved, and the durability of the bead wire and the durability of the tire can be improved by suppressing the occurrence of rust.
- the rubber permeability can be improved to some extent, but in the case of a bundle-twisted structure, the position of the strand is randomly changed, so a gap is formed by the typed strand. Is also unstable and the rubber permeability is low.
- the effect of improving the rubber permeability is higher than that of the bundle twisted structure, for example, the gaps are stably formed because the positions of the strands are not interchanged.
- the twisted bead wire has the advantage of the bundle twist structure that can increase the fitting force with the rim and maintain the steering stability, and the bundle twist that is inferior in air leak resistance and rubber permeability.
- the fitting force with the rim, the air leak resistance, and the rubber permeability Bead deformation during rim assembly can be suppressed.
- the pneumatic tire 1 of the present embodiment includes a carcass 6 that extends from a tread portion 2 through a sidewall portion 3 to a bead core 5 of a bead portion 4.
- the radial direction of the carcass 6 is provided.
- a belt layer 7 is provided outside and inside the tread portion 2.
- the belt layer 7 is formed of one or more, in this example, two belt plies 7A and 7B in which belt cords are arranged at an angle of, for example, 10 to 35 ° with respect to the tire circumferential direction.
- the belt layer 7 increases belt rigidity by crossing the belt cords between the plies, and reinforces substantially the entire width of the tread portion 2 with a tagging effect.
- a steel cord is used as the belt cord, but high modulus organic fiber cords such as polyethylene naphthalate (PEN), polyethylene terephthalate (PET), and aromatic polyamide may be used as necessary.
- PEN polyethylene naphthalate
- PET polyethylene terephthalate
- aromatic polyamide aromatic polyamide
- a band in which a band cord of an organic fiber such as nylon is spirally wound at an angle of 5 degrees or less with respect to the circumferential direction for the purpose of improving high-speed durability.
- a layer 9 can be provided.
- the band layer 9 a pair of left and right edge band plies that covers only the outer end portion of the belt layer 7 in the tire axial direction and a full band ply that covers substantially the entire width of the belt layer 7 can be used as appropriate. An example of a single full band ply is shown.
- the carcass 6 is formed of one or more carcass ply bodies 6A in the present example in which organic fiber carcass cords are radially arranged.
- the carcass ply body 6A has a toroidal shape straddling the bead portions 4 and 4, and both radial end portions 6AE are sandwiched and locked in the bead core 5 without being folded around the bead core 5.
- the bead core 5 is composed of inner and outer core pieces 5i and 5o in the tire axial direction, and both radial end portions 6AE of the carcass ply 6A are sandwiched between the inner and outer core pieces 5i and 5o.
- the inner and outer core pieces 5i, 5o are thin spiral bodies in which the bead wire 5a is spirally wound from the radially inner side to the outer side to a height position beyond the radially outer end of the rim flange RF. Formed from. That is, the radial heights H1 and H2 from the bead base line BL on the radially outer peripheral surfaces of the core pieces 5i and 5o are larger than the radial height Hr from the bead base line BL at the outer end of the rim flange Rf. It is.
- the core pieces 5i and 5o of this example are formed in a row in the tire axial direction, and thereby the radial heights H1 and H2 of the core pieces 5i and 5o are maximized within the limited number of turns of the bead wire 5a.
- the contact area with the carcass ply 6A can be increased, and the locking force to the carcass ply both ends 6AE is secured.
- the winding number No of the bead wire 5a in the outer core piece 5o is set to be equal to or less than the winding number Ni in the inner core piece 5i.
- the bead portion 4 is provided with inner and outer bead apex rubbers 8i and 8o extending radially outward from the inner and outer core pieces 5i and 5o, respectively, and is reinforced from the bead portion 4 to the sidewall portion 3. is doing.
- Reference numeral 10 in the figure denotes a chafer rubber for preventing rim displacement.
- the bead wire 5a is formed by twisting a plurality of steel strands 11 in order to prevent core deformation when assembling the rim.
- the bead wire 5 a is formed by twisting a core portion 12 obtained by twisting two or more core strands 11 c and three or more sheath strands 11 s around the core portion 12.
- the twisted direction and the twist pitch Pc of the core strand 11c are the same as the twist direction and the twist pitch Ps of the sheath strand 11s.
- FIG. 3 shows a case where the bead wire 5a is composed of two core strands 11c and seven sheath strands 11s.
- the twist direction and the twist pitch Pc of the core strand 11c are the same as the twist direction and the twist pitch Ps of the sheath strand 11s, so that the plurality of strands 11 are the most compact. And are twisted together while maintaining this arrangement state. That is, the arrangement state of the strands 11 in the wire cross section is the same at an arbitrary position in the length direction of the bead wire 5a, and the same arrangement state is shifted around the center of the wire.
- the rubber permeability can be improved to some extent, but in the case of a bundle-twisted structure, the position of the strand is randomly changed, so a gap is formed by the typed strand. Is also unstable and the rubber permeability is low.
- the effect of improving the rubber permeability is higher than that of the bundle twisted structure, for example, the gaps are stably formed because the positions of the strands are not interchanged.
- the bead wire 5a has a bundle twist structure that is inferior in air leak resistance and rubber permeability while exhibiting the advantage of the bundle twist structure that can increase the fitting force with the rim and maintain the steering stability.
- Bead deformation can be suppressed.
- the wire diameter of the wire 11 is not particularly limited, but in the case of a passenger car tire, a range of 0.175 to 0.45 mm is preferably employed from the viewpoint of the required strength of the bead wire.
- the number of core strands 11c and the number of sheath strands 11s are not particularly limited, but in the case of a tire for passenger cars, the number of core strands 11c ranges from 2 to 5 in the case of tires for passenger cars.
- the number of lines 11s is larger than that and is preferably in the range of 3 to 12.
- the core portion 12 is loosely inserted into the center of the second twisting die 21.
- the loose insertion hole 21b opens.
- Qs is a converging position of the sheath wire 11s and is located downstream of the converging position Qc of the core wire 11c.
- the bead wire 5a with equal twist pitch Pc and Ps can be formed by adjusting the rotation speed of the 1st, 2nd twisting die
- this manufacturing method uses a rigid core 30 provided on the outer surface with a tire forming surface 30s that forms a lumen surface of the pneumatic tire 1, and on the tire forming surface 30s.
- the raw tire forming step S1 for forming the raw tire 1N by sequentially pasting the unvulcanized tire constituent members, and the raw tire 1N together with the rigid core 30 are put into the vulcanizing mold and vulcanized. And a vulcanizing step (not shown).
- the rubber cored bead wire 5a covered with unvulcanized rubber is spirally wound from the inner side to the outer side in the radial direction and attached to form the inner core piece 5i.
- the bead wire 5a has the twist structure in which the twist direction and the twist pitch Pc of the core wire 11c are the same as the twist direction and the twist pitch Ps of the sheath wire 11s.
- a bundle of m strands is a 1 ⁇ m structure
- a layer twist of m core strands and n sheath strands is an m + n structure
- the m core strands The twisted structure of the present embodiment, in which the twisted wire and the n sheath strands are twisted together with the same twisting direction and twist pitch, is described as the m / n structure.
- Each tire has substantially the same specifications except for the bead wire specifications shown in Table 1.
- the main common specifications are as follows. ⁇ Carcass> Number of carcass plies: 1 Carcass cord material: Polyester Carcass cord angle: 88 ° (against tire equator) ⁇ Belt layer> Number of belt plies: 2 Belt cord material: Steel Belt cord angle: + 28 °, -28 ° (against tire equator) ⁇ Bead core> Number of windings of bead wire in inner core piece Ni: 8 Number of windings of bead wire in outer core piece No: 11 Rubber hardness of bead apex rubber: 80 degrees (durometer A hardness)
- ⁇ Strong code> Based on the tensile test defined in “JIS G3510“ Steel Tire Cord Test Method ”, the maximum tensile load until the cord breaks was measured. The distance between the grips is 700 mm, and the pulling speed is 50 mm / min. " ⁇ Bending rigidity> “When a force is applied to the tip of the cord extending 5 cm from the fixed end using the V-5 stiffness tester 150-D manufactured by TABER (USA), and the opening angle ⁇ of the tip becomes 15 ° It is defined as the value of the bending moment (gf ⁇ cm). ⁇ Twist pool> Whether the wire floats or not when the cord is rubberized was visually evaluated.
- Air leak resistance of the bead core The rate of decrease in internal pressure when the tire is mounted on a rim (15 ⁇ 6 JJ) and filled with 200 kPa of internal pressure and left to stand for 30 days is indicated by an index with the conventional tire as 100. The larger the value, the better the air leak resistance.
- Tires are mounted on all wheels of a vehicle (2000cc) under conditions of rim (15x6JJ) and internal pressure (200 kPa), run on a test track on a dry paved road, drive straight, stability during turning, braking
- the behavior of the vehicle at the time was comprehensively judged by sensory evaluation by a professional driver.
- the evaluation is indicated by an index with the conventional tire as 100. The larger the value, the better the steering stability.
- the cords of the examples can suppress the bead deformation at the time of assembling the rim without causing a decrease in fitting force with the rim, air leak resistance, and rubber permeability.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Tires In General (AREA)
- Tyre Moulding (AREA)
- Ropes Or Cables (AREA)
Abstract
The present invention prevents core deformation during rim assembly while corrosion resistance and air-leak resistance are assured in a tire made by a core making process. A bead core comprises inner and outer core pieces in the tire axial direction, and a radial inner end part of a carcass ply is held therebetween. The inner and outer bead pieces are composed of a spiral-wound body in which a bead wire has been wound in an overlapping manner in the shape of spiral. The bead wire is composed of a core part in which core strands have been twisted together, and a sheath part in which sheath strands have been twisted together around the core part. The core strands and/or the sheath strands include embossed strands. The twisting direction and twisting pitch (Pc) of the core strands are the same as the twisting direction and twitching pitch (Ps) of the sheath strands.
Description
本発明は、カーカスプライの半径方向内端部をタイヤ軸方向内外のコア片間で狭持させたビード構造を有する空気入りタイヤ、及びその製造方法に関する。
The present invention relates to a pneumatic tire having a bead structure in which a radially inner end portion of a carcass ply is sandwiched between core pieces inside and outside in the tire axial direction, and a manufacturing method thereof.
近年、タイヤの形成精度を高めるため、図8(A)に示すように、加硫済みタイヤのタイヤ内面形状に相当する外面形状を有する剛性中子aを用い、この剛性中子a上に、インナーライナ、カーカスプライ、ビードコア、ベルトプライ、サイドウォールゴム、トレッドゴム等のタイヤ構成部材を順次貼り付けて未加硫タイヤtを形成するとともに、この未加硫タイヤtを剛性中子aごと加硫金型b内に投入し、内型である剛性中子aと外型である加硫金型bとの間でタイヤを加硫成形する工法(以下、中子工法という場合がある。)が提案されている。
In recent years, in order to increase the formation accuracy of the tire, as shown in FIG. 8 (A), a rigid core a having an outer surface shape corresponding to the tire inner surface shape of the vulcanized tire is used. A tire component such as an inner liner, carcass ply, bead core, belt ply, sidewall rubber, and tread rubber is sequentially attached to form an unvulcanized tire t, and this unvulcanized tire t is added together with a rigid core a. A construction method in which a tire is vulcanized and molded between a rigid core a as an inner mold and a vulcanization mold b as an outer mold (hereinafter sometimes referred to as a core construction method). Has been proposed.
この中子工法では、従来タイヤの如くカーカスプライの両端部をビードコアの廻りで折り返して係止させることが難しい。そのため、下記の特許文献1には図8(B)に示すように、ビードコアdをタイヤ軸方向内外のコア片d1、d2に分割し、カーカスプライcの両端部を折り返さずに前記内外のコア片d1、d2間で狭圧して保持する構造が提案されている。このコア片d1、d2は、単線のビードワイヤeをタイヤ半径方向の内側から外側に渦巻き状に巻き重ねた薄い渦巻き体として形成される。これにより、限られたビードワイヤeの巻回数の中でビードコアdの半径方向高さを最大限に高めることができ、カーカスプライとの接触面積を増し、カーカスプライ両端部への係止力を確保することができる。
In this core method, it is difficult to fold and lock both ends of the carcass ply around the bead core as in the conventional tire. Therefore, in Patent Document 1 below, as shown in FIG. 8B, the bead core d is divided into inner and outer core pieces d1, d2 in the tire axial direction, and the inner and outer cores are not folded back without folding both ends of the carcass ply c. A structure has been proposed in which a pressure is held between the pieces d1 and d2. The core pieces d1 and d2 are formed as a thin spiral body in which a single bead wire e is spirally wound from the inner side to the outer side in the tire radial direction. As a result, the radial height of the bead core d can be maximized within a limited number of turns of the bead wire e, the contact area with the carcass ply is increased, and the locking force to both ends of the carcass ply is secured. can do.
しかしながらこのようなビード構造の場合、前記コア片d1、d2のタイヤ軸方向の厚さが小であるため、リム組み時、ビード部をレバーで捻る際に局部的な変形が発生し、これが塑性変形となってリム組み後も元の形状に戻らないという問題がある。
However, in the case of such a bead structure, since the thickness of the core pieces d1, d2 in the tire axial direction is small, when the rim is assembled, local deformation occurs when the bead portion is twisted with a lever, which is plastic. There is a problem that it becomes deformed and does not return to its original shape after assembling the rim.
そこで本発明は、ビードワイヤとして単線ワイヤに代えて、複数本のスチール製の素線を用いた所定撚り構造のものを採用することを基本として、耐腐食性や耐エアリーク性を確保しながら、ビードワイヤに適度なしなやかさを付与してリム組み時のコア変形を防止しうる空気入りタイヤ、及びその製造方法を提供することを目的としている。
Therefore, the present invention is based on adopting a predetermined twisted structure using a plurality of steel strands instead of a single wire as a bead wire, while ensuring corrosion resistance and air leak resistance, It is an object of the present invention to provide a pneumatic tire capable of preventing the core deformation during assembling of the rim by imparting moderate flexibility to the tire, and a method for manufacturing the same.
上記課題を解決するために、本願請求項1の発明は、トレッド部からサイドウォール部をへてビード部のビードコアに至るカーカスプライからなるカーカスを具える空気入りタイヤであって、
前記ビードコアは、タイヤ軸方向内外のコア片からなり、かつ前記カーカスプライの半径方向内端部が、ビードコアの廻りで折り返されることなく前記内外のコア片間で狭持されるとともに、
前記内外のコア片は、線径同一の複数本のスチール製の素線を撚り合わせたビードワイヤを、半径方向内側から外側にリムフランジの半径方向外端を越えた高さ位置まで渦巻き状に巻き重ねた渦巻き体からなり、
しかも前記ビードワイヤは、2本以上のコア素線を撚り合わせたコア部と、3本以上のシース素線を前記コア部の回りで撚り合わせたシース部とからなり、かつ前記コア素線及び/又はシース素線は、撚り合わされる前の状態で螺旋状又は波形状に型付けされた型付け素線を含むとともに、
前記コア素線の撚り方向及び撚りピッチPcを、前記シース素線の撚り方向及び撚りピッチPsと同一としたことを特徴としている。 In order to solve the above-mentioned problem, the invention ofclaim 1 of the present application is a pneumatic tire comprising a carcass made of a carcass ply extending from a tread portion to a bead core of a bead portion through a sidewall portion,
The bead core is composed of inner and outer core pieces in the tire axial direction, and the radially inner end portion of the carcass ply is sandwiched between the inner and outer core pieces without being folded around the bead core,
The inner and outer core pieces are spirally wound with a bead wire formed by twisting together a plurality of steel strands having the same wire diameter from the inside in the radial direction to the outside to the height position beyond the radially outer end of the rim flange. Consisting of stacked spiral bodies,
In addition, the bead wire includes a core portion obtained by twisting two or more core strands and a sheath portion obtained by twisting three or more sheath strands around the core portion, and the core strand and / or Alternatively, the sheath wire includes a shaped wire that is shaped in a spiral or wave shape before being twisted, and
The twist direction and twist pitch Pc of the core strand are the same as the twist direction and twist pitch Ps of the sheath strand.
前記ビードコアは、タイヤ軸方向内外のコア片からなり、かつ前記カーカスプライの半径方向内端部が、ビードコアの廻りで折り返されることなく前記内外のコア片間で狭持されるとともに、
前記内外のコア片は、線径同一の複数本のスチール製の素線を撚り合わせたビードワイヤを、半径方向内側から外側にリムフランジの半径方向外端を越えた高さ位置まで渦巻き状に巻き重ねた渦巻き体からなり、
しかも前記ビードワイヤは、2本以上のコア素線を撚り合わせたコア部と、3本以上のシース素線を前記コア部の回りで撚り合わせたシース部とからなり、かつ前記コア素線及び/又はシース素線は、撚り合わされる前の状態で螺旋状又は波形状に型付けされた型付け素線を含むとともに、
前記コア素線の撚り方向及び撚りピッチPcを、前記シース素線の撚り方向及び撚りピッチPsと同一としたことを特徴としている。 In order to solve the above-mentioned problem, the invention of
The bead core is composed of inner and outer core pieces in the tire axial direction, and the radially inner end portion of the carcass ply is sandwiched between the inner and outer core pieces without being folded around the bead core,
The inner and outer core pieces are spirally wound with a bead wire formed by twisting together a plurality of steel strands having the same wire diameter from the inside in the radial direction to the outside to the height position beyond the radially outer end of the rim flange. Consisting of stacked spiral bodies,
In addition, the bead wire includes a core portion obtained by twisting two or more core strands and a sheath portion obtained by twisting three or more sheath strands around the core portion, and the core strand and / or Alternatively, the sheath wire includes a shaped wire that is shaped in a spiral or wave shape before being twisted, and
The twist direction and twist pitch Pc of the core strand are the same as the twist direction and twist pitch Ps of the sheath strand.
又請求項3の発明は、トレッド部からサイドウォール部をへてビード部のビードコアに至るカーカスプライからなるカーカスを具える空気入りタイヤの製造方法であって、
外表面に空気入りタイヤの内腔面を形成するタイヤ形成面を設けた剛性中子を用い、前記タイヤ形成面上に、ビードコアとカーカスプライとを含む未加硫のタイヤ構成部材を順次貼り付けることにより生タイヤを形成する生タイヤ形成工程を具えるとともに、
この生タイヤ形成工程は、前記タイヤ形成面上で、未加硫のゴムで被覆されたゴム引きのビードワイヤを半径方向内側から外側に渦巻き状に巻き重ねて貼り付けて内のコア片を形成する第1のコア片工程と、
前記内のコア片のタイヤ軸方向外側にカーカスプライの半径方向内端部を貼付けるステップを有するカーカス形成工程と、
前記カーカスプライの半径方向内端部のタイヤ軸方向外側に、前記ゴム引きのビードワイヤを半径方向内側から外側に渦巻き状に巻き重ねて貼り付けて外のコア片を形成する第2のコア片工程とを含み、
しかも前記ビードワイヤは、2本以上のコア素線を撚り合わせたコア部と、3本以上のシース素線を前記コア部の回りで撚り合わせたシース部とからなり、かつ前記コア素線及び/又はシース素線は、撚り合わされる前の状態で螺旋状又は波形状に型付けされた型付け素線を含むとともに、
前記コア素線の撚り方向及び撚りピッチPcを、前記シース素線の撚り方向及び撚りピッチPsと同一としたことを特徴としている。 The invention ofclaim 3 is a method for producing a pneumatic tire comprising a carcass made of a carcass ply extending from a tread portion through a sidewall portion to a bead core of the bead portion,
Using a rigid core provided with a tire forming surface that forms the inner cavity surface of a pneumatic tire on the outer surface, unvulcanized tire components including a bead core and a carcass ply are sequentially pasted on the tire forming surface. In addition to providing a raw tire forming process to form a raw tire by
In the green tire forming step, a rubber-coated bead wire coated with unvulcanized rubber is spirally wound from the inside in the radial direction to the outside on the tire forming surface to form an inner core piece. A first core piece process;
A carcass forming step having a step of sticking a radially inner end portion of the carcass ply to the outer side in the tire axial direction of the inner core piece;
A second core piece step of forming an outer core piece by winding and sticking the rubberized bead wire on the outer side in the tire axial direction of the radially inner end of the carcass ply in a spiral shape from the inner side to the outer side in the radial direction Including
In addition, the bead wire includes a core portion obtained by twisting two or more core strands and a sheath portion obtained by twisting three or more sheath strands around the core portion, and the core strand and / or Alternatively, the sheath wire includes a shaped wire that is shaped in a spiral or wave shape before being twisted, and
The twist direction and twist pitch Pc of the core strand are the same as the twist direction and twist pitch Ps of the sheath strand.
外表面に空気入りタイヤの内腔面を形成するタイヤ形成面を設けた剛性中子を用い、前記タイヤ形成面上に、ビードコアとカーカスプライとを含む未加硫のタイヤ構成部材を順次貼り付けることにより生タイヤを形成する生タイヤ形成工程を具えるとともに、
この生タイヤ形成工程は、前記タイヤ形成面上で、未加硫のゴムで被覆されたゴム引きのビードワイヤを半径方向内側から外側に渦巻き状に巻き重ねて貼り付けて内のコア片を形成する第1のコア片工程と、
前記内のコア片のタイヤ軸方向外側にカーカスプライの半径方向内端部を貼付けるステップを有するカーカス形成工程と、
前記カーカスプライの半径方向内端部のタイヤ軸方向外側に、前記ゴム引きのビードワイヤを半径方向内側から外側に渦巻き状に巻き重ねて貼り付けて外のコア片を形成する第2のコア片工程とを含み、
しかも前記ビードワイヤは、2本以上のコア素線を撚り合わせたコア部と、3本以上のシース素線を前記コア部の回りで撚り合わせたシース部とからなり、かつ前記コア素線及び/又はシース素線は、撚り合わされる前の状態で螺旋状又は波形状に型付けされた型付け素線を含むとともに、
前記コア素線の撚り方向及び撚りピッチPcを、前記シース素線の撚り方向及び撚りピッチPsと同一としたことを特徴としている。 The invention of
Using a rigid core provided with a tire forming surface that forms the inner cavity surface of a pneumatic tire on the outer surface, unvulcanized tire components including a bead core and a carcass ply are sequentially pasted on the tire forming surface. In addition to providing a raw tire forming process to form a raw tire by
In the green tire forming step, a rubber-coated bead wire coated with unvulcanized rubber is spirally wound from the inside in the radial direction to the outside on the tire forming surface to form an inner core piece. A first core piece process;
A carcass forming step having a step of sticking a radially inner end portion of the carcass ply to the outer side in the tire axial direction of the inner core piece;
A second core piece step of forming an outer core piece by winding and sticking the rubberized bead wire on the outer side in the tire axial direction of the radially inner end of the carcass ply in a spiral shape from the inner side to the outer side in the radial direction Including
In addition, the bead wire includes a core portion obtained by twisting two or more core strands and a sheath portion obtained by twisting three or more sheath strands around the core portion, and the core strand and / or Alternatively, the sheath wire includes a shaped wire that is shaped in a spiral or wave shape before being twisted, and
The twist direction and twist pitch Pc of the core strand are the same as the twist direction and twist pitch Ps of the sheath strand.
又請求項2、4の発明では、前記ビードワイヤは、前記コア素線が撚り合わされた後、コア部の周囲にシース素線が巻き付けられることを特徴としている。
In the inventions of claims 2 and 4, the bead wire is characterized in that after the core strands are twisted together, a sheath strand is wound around the core portion.
本発明は叙上の如く、カーカスプライの半径方向内端部を、タイヤ軸方向内外のコア片間で狭圧させたビード構造において、各コア片を、ビードワイヤをリムフランジの半径方向外端を越えた高さ位置まで渦巻き状に巻き重ねた渦巻き体にて形成している。従って、コア片とカーカスプライとの接触面積を高めて係止力を充分に発揮させることができ、カーカスプライの吹き抜けを防止しうる。
As described above, according to the present invention, in the bead structure in which the inner end of the carcass ply in the radial direction is narrowed between the inner and outer core pieces, each core piece is connected to the outer end in the radial direction of the rim flange. It is formed of a spiral body that is spirally wound up to a height position that exceeds it. Therefore, the contact area between the core piece and the carcass ply can be increased to sufficiently exert the locking force, and the carcass ply can be prevented from being blown out.
又前記ビードワイヤとして、コア素線を撚り合わせたコア部と、シース素線を前記コア部の回りで撚り合わせたシース部とからなり、しかも前記コア素線の撚り方向及び撚りピッチPcを、前記シース素線の撚り方向及び撚りピッチPsと同一とした撚り構造を採用している。これにより、ビードワイヤに適度なしなやかさを付与でき、リム組み時のコア変形を防止しうる。
The bead wire includes a core portion obtained by twisting core strands and a sheath portion obtained by twisting sheath strands around the core portion, and the twist direction and twist pitch Pc of the core strands are A twist structure that is the same as the twist direction and the twist pitch Ps of the sheath wire is employed. Thereby, moderate flexibility can be given to a bead wire, and core deformation at the time of rim assembly can be prevented.
しかもこのものは、コア素線とシース素線とにおいて、撚り方向及び撚りピッチが互いに同一であるため、複数本の素線を束ねて撚り合わせた所謂束撚り構造と同様、最もコンパクトに素線を撚り合わすことができる。そのため、ワイヤ内でのスペースの形成が少なくなり、ワイヤ断面形状が変化する向きの変形を低く抑えることができ、リムとの嵌合力を高めて操縦安定性を維持することができる。なお撚り方向或いは撚りピッチの少なくとも一方を相違させた通常の層撚り構造の場合には、コア部内にシース素線が落ち込むスペースが形成されるため、リムとの嵌合力が減じ操縦安定性に悪影響を与える。
In addition, since the core strand and the sheath strand have the same twisting direction and twisting pitch, the strands are the most compact in the same manner as a so-called bundle twist structure in which a plurality of strands are bundled and twisted together. Can be twisted together. Therefore, the formation of a space in the wire is reduced, deformation in the direction in which the wire cross-sectional shape changes can be kept low, and the fitting force with the rim can be increased to maintain steering stability. In the case of a normal layer twist structure in which at least one of the twist direction or the twist pitch is different, a space for the sheath wire to fall in the core portion is formed, so that the fitting force with the rim is reduced and the steering stability is adversely affected. give.
又束撚り構造では、ワイヤ内で素線の位置がランダムに入れ替わるため断面形状が周方向に不均一となる。そのため周方向において、リムとの嵌合圧が強い所と弱いところが形成される傾向があり、この嵌合圧の弱い所から充填空気が漏れやすくなるなど耐エアーリーク性の低下を招く。これに対して、前記撚り構造は、素線の位置が入れ替わることがなく断面形状が周方向に安定しているため、耐エアーリーク性を高く維持することができる。
In addition, in the bundle twist structure, the position of the strands is randomly changed in the wire, so that the cross-sectional shape is not uniform in the circumferential direction. Therefore, in the circumferential direction, there is a tendency that a place where the fitting pressure with the rim is strong and a weak place are formed, and the air leakage resistance is deteriorated such that the filling air easily leaks from the place where the fitting pressure is weak. On the other hand, in the twisted structure, the position of the strand does not change and the cross-sectional shape is stable in the circumferential direction, so that the air leak resistance can be kept high.
さらに前記ビードワイヤでは、型付け素線を含むためワイヤ内へのゴム浸透性を高めることができ、錆の発生を抑えてビードワイヤの耐久性、ひいてはタイヤの耐久性を向上することができる。なお束撚り構造において型付け素線を用いた場合にも、ある程度ゴム浸透性を高めることができるものの、束撚り構造の場合には、素線の位置がランダムに入れ替わるため型付け素線による隙間の形成も不安定であり、ゴム浸透性が低くなる。これに対して前記撚り構造の場合には、素線の位置が入れ替わらないため隙間が安定して形成されるなど、束撚り構造に比してゴム浸透性への向上効果は高くなる。
Further, since the bead wire includes the embossed element wire, the rubber penetration into the wire can be improved, and the durability of the bead wire and the durability of the tire can be improved by suppressing the occurrence of rust. In addition, even when using a typed strand in a bundle-twisted structure, the rubber permeability can be improved to some extent, but in the case of a bundle-twisted structure, the position of the strand is randomly changed, so a gap is formed by the typed strand. Is also unstable and the rubber permeability is low. On the other hand, in the case of the twisted structure, the effect of improving the rubber permeability is higher than that of the bundle twisted structure, for example, the gaps are stably formed because the positions of the strands are not interchanged.
このように、前記撚り構造のビードワイヤは、リムとの嵌合力を高めて操縦安定性を維持しうるという束撚り構造の利点を発揮しながら、耐エアーリーク性、ゴム浸透性に劣るという束撚り構造が有する欠点を補うことができ、中子工法で形成される空気入りタイヤにおいて、カーカスプライの吹き抜け性、リムとの嵌合力、耐エアーリーク性、及びゴム浸透性の低下を招くことなく、リム組時のビード変形を抑えることができる。
As described above, the twisted bead wire has the advantage of the bundle twist structure that can increase the fitting force with the rim and maintain the steering stability, and the bundle twist that is inferior in air leak resistance and rubber permeability. In the pneumatic tire formed by the core method, which can compensate for the drawbacks of the structure, without causing a decrease in the blow-through property of the carcass ply, the fitting force with the rim, the air leak resistance, and the rubber permeability. Bead deformation during rim assembly can be suppressed.
以下、本発明の実施の形態について、詳細に説明する。
図1に示すように、本実施形態の空気入りタイヤ1は、トレッド部2からサイドウォール部3をへてビード部4のビードコア5に至るカーカス6を具え、本例ではこのカーカス6の半径方向外側かつトレッド部2の内部にベルト層7を設けている。 Hereinafter, embodiments of the present invention will be described in detail.
As shown in FIG. 1, thepneumatic tire 1 of the present embodiment includes a carcass 6 that extends from a tread portion 2 through a sidewall portion 3 to a bead core 5 of a bead portion 4. In this example, the radial direction of the carcass 6 is provided. A belt layer 7 is provided outside and inside the tread portion 2.
図1に示すように、本実施形態の空気入りタイヤ1は、トレッド部2からサイドウォール部3をへてビード部4のビードコア5に至るカーカス6を具え、本例ではこのカーカス6の半径方向外側かつトレッド部2の内部にベルト層7を設けている。 Hereinafter, embodiments of the present invention will be described in detail.
As shown in FIG. 1, the
前記ベルト層7は、ベルトコードをタイヤ周方向に対して例えば10~35゜の角度で配列した1枚以上、本例では2枚のベルトプライ7A、7Bから形成される。このベルト層7は、各ベルトコードがプライ間相互で交差することによりベルト剛性を高め、トレッド部2の略全巾をタガ効果を有して強固に補強する。なお、前記ベルトコードとして本例ではスチールコードを採用しているが、ポリエチレンナフタレート(PEN)、ポリエチレンテレフタレート(PET)、芳香族ポリアミド等の高モジュラスの有機繊維コードも必要に応じて用いうる。
The belt layer 7 is formed of one or more, in this example, two belt plies 7A and 7B in which belt cords are arranged at an angle of, for example, 10 to 35 ° with respect to the tire circumferential direction. The belt layer 7 increases belt rigidity by crossing the belt cords between the plies, and reinforces substantially the entire width of the tread portion 2 with a tagging effect. In this example, a steel cord is used as the belt cord, but high modulus organic fiber cords such as polyethylene naphthalate (PEN), polyethylene terephthalate (PET), and aromatic polyamide may be used as necessary.
又このベルト層7の半径方向外側には、高速耐久性などを高める目的で、例えばナイロン等の有機繊維のバンドコードを周方向に対して5度以下の角度で螺旋状に巻回させたバンド層9を設けることができる。このバンド層9として、前記ベルト層7のタイヤ軸方向外端部のみを被覆する左右一対のエッジバンドプライ、及びベルト層7の略全巾を覆うフルバンドプライが適宜使用でき、本例では1枚のフルバンドプライからなるものを例示している。
Also, on the outer side of the belt layer 7 in the radial direction, for example, a band in which a band cord of an organic fiber such as nylon is spirally wound at an angle of 5 degrees or less with respect to the circumferential direction for the purpose of improving high-speed durability. A layer 9 can be provided. As the band layer 9, a pair of left and right edge band plies that covers only the outer end portion of the belt layer 7 in the tire axial direction and a full band ply that covers substantially the entire width of the belt layer 7 can be used as appropriate. An example of a single full band ply is shown.
次に、前記カーカス6は、有機繊維のカーカスコードをラジアル配列させた1枚以上、本例では1枚のカーカスプライ体6Aから形成される。このカーカスプライ体6Aは、前記ビード部4、4間を跨るトロイド状をなすとともに、その半径方向両端部6AEは、前記ビードコア5の廻りで折り返されることなく該ビードコア5内に挟まれて係止されている。具体的には、前記ビードコア5は、タイヤ軸方向内外のコア片5i、5oからなり、この内外のコア片5i、5o間で、前記カーカスプライ6Aの半径方向両端部6AEが狭持される。
Next, the carcass 6 is formed of one or more carcass ply bodies 6A in the present example in which organic fiber carcass cords are radially arranged. The carcass ply body 6A has a toroidal shape straddling the bead portions 4 and 4, and both radial end portions 6AE are sandwiched and locked in the bead core 5 without being folded around the bead core 5. Has been. Specifically, the bead core 5 is composed of inner and outer core pieces 5i and 5o in the tire axial direction, and both radial end portions 6AE of the carcass ply 6A are sandwiched between the inner and outer core pieces 5i and 5o.
前記内外のコア片5i、5oは、図2に示すように、ビードワイヤ5aを半径方向内側から外側にリムフランジRFの半径方向外端を越えた高さ位置まで渦巻き状に巻き重ねた薄い渦巻き体から形成される。即ち、前記コア片5i、5oの半径方向外周面のビードベースラインBLからの半径方向高さH1、H2は、リムフランジRfの外端のビードベースラインBLからの半径方向高さHrよりも大である。本例のコア片5i、5oは、タイヤ軸方向には一列で形成され、これにより限られたビードワイヤ5aの巻回数の中でコア片5i、5oの半径方向高さH1、H2を最大限に高めることができ、カーカスプライ6Aとの接触面積を増し、カーカスプライ両端部6AEへの係止力を確保している。
As shown in FIG. 2, the inner and outer core pieces 5i, 5o are thin spiral bodies in which the bead wire 5a is spirally wound from the radially inner side to the outer side to a height position beyond the radially outer end of the rim flange RF. Formed from. That is, the radial heights H1 and H2 from the bead base line BL on the radially outer peripheral surfaces of the core pieces 5i and 5o are larger than the radial height Hr from the bead base line BL at the outer end of the rim flange Rf. It is. The core pieces 5i and 5o of this example are formed in a row in the tire axial direction, and thereby the radial heights H1 and H2 of the core pieces 5i and 5o are maximized within the limited number of turns of the bead wire 5a. The contact area with the carcass ply 6A can be increased, and the locking force to the carcass ply both ends 6AE is secured.
本例では、タイヤ変形時のコア崩れを防止するため、外のコア片5oにおけるビードワイヤ5aの巻回数Noを、内のコア片5iにおける巻回数Ni以下としている。又ビード部4には、内外のコア片5i、5oからそれぞれ半径方外側に向かって先細状にのびる内、外のビードエーペックスゴム8i、8oが設けられ、ビード部4からサイドウォール部3にかけて補強している。なお図中の符号10は、リムずれ防止用のチェーファーゴムである。
In this example, in order to prevent core collapse at the time of tire deformation, the winding number No of the bead wire 5a in the outer core piece 5o is set to be equal to or less than the winding number Ni in the inner core piece 5i. The bead portion 4 is provided with inner and outer bead apex rubbers 8i and 8o extending radially outward from the inner and outer core pieces 5i and 5o, respectively, and is reinforced from the bead portion 4 to the sidewall portion 3. is doing. Reference numeral 10 in the figure denotes a chafer rubber for preventing rim displacement.
次に、前記ビードワイヤ5aでは、リム組み時のコア変形を防止するため、複数本のスチール製の素線11を撚り合わせて形成される。具体的には、ビードワイヤ5aは、図3に示すように、2本以上のコア素線11cを撚り合わせたコア部12と、3本以上のシース素線11sを前記コア部12の回りで撚り合わせたシース部13とから形成されるとともに、前記コア素線11cの撚り方向及び撚りピッチPcを、前記シース素線11sの撚り方向及び撚りピッチPsと同一としている。同図3には、前記ビードワイヤ5aが、2本のコア素線11cと7本のシース素線11sとから構成される場合が示されている。
Next, the bead wire 5a is formed by twisting a plurality of steel strands 11 in order to prevent core deformation when assembling the rim. Specifically, as shown in FIG. 3, the bead wire 5 a is formed by twisting a core portion 12 obtained by twisting two or more core strands 11 c and three or more sheath strands 11 s around the core portion 12. The twisted direction and the twist pitch Pc of the core strand 11c are the same as the twist direction and the twist pitch Ps of the sheath strand 11s. FIG. 3 shows a case where the bead wire 5a is composed of two core strands 11c and seven sheath strands 11s.
このような本実施形態の撚り構造では、コア素線11cの撚り方向及び撚りピッチPcを、シース素線11sの撚り方向及び撚りピッチPsと同一としているため、複数本の素線11が最もコンパクトに配列するとともに、この配列状態を維持しながら撚り合わされる。即ち、ワイヤ断面における素線11の配列状態は、ビードワイヤ5aの長さ方向の任意の位置において同一であって、同じ配列状態がワイヤ中心回りでシフトしたものとなる。
In such a twisted structure of the present embodiment, the twist direction and the twist pitch Pc of the core strand 11c are the same as the twist direction and the twist pitch Ps of the sheath strand 11s, so that the plurality of strands 11 are the most compact. And are twisted together while maintaining this arrangement state. That is, the arrangement state of the strands 11 in the wire cross section is the same at an arbitrary position in the length direction of the bead wire 5a, and the same arrangement state is shifted around the center of the wire.
これに対して束撚り構造の場合には、素線が最もコンパクトに配列するものの、ワイヤ内で素線の位置がランダムに入れ替わるため、素線の配列状態は長さ方向に種々変化する。そのため、断面形状が周方向に不均一となるなど、周方向においてリムとの嵌合圧が強い所と弱いところが形成される傾向があり、この嵌合圧の弱い所から充填空気が漏れやすくなるなど耐エアーリーク性の低下を招く。これに対して、本実施形態の撚り構造は、素線の位置が入れ替わることがなく断面形状が周方向に安定しているため、耐エアーリーク性を高く維持することができる。
On the other hand, in the case of the bundle-twisted structure, the strands are arranged in the most compact manner, but the strands are randomly switched in the wire, so that the strand arrangement state varies in the length direction. For this reason, there is a tendency that places where the fitting pressure with the rim is strong and weak in the circumferential direction are formed, such as the cross-sectional shape being uneven in the circumferential direction, and the filling air is likely to leak from the place where the fitting pressure is weak. It causes a decrease in air leak resistance. On the other hand, the twisted structure of the present embodiment can maintain high air leak resistance because the position of the strand does not change and the cross-sectional shape is stable in the circumferential direction.
On the other hand, in the case of the bundle-twisted structure, the strands are arranged in the most compact manner, but the strands are randomly switched in the wire, so that the strand arrangement state varies in the length direction. For this reason, there is a tendency that places where the fitting pressure with the rim is strong and weak in the circumferential direction are formed, such as the cross-sectional shape being uneven in the circumferential direction, and the filling air is likely to leak from the place where the fitting pressure is weak. It causes a decrease in air leak resistance. On the other hand, the twisted structure of the present embodiment can maintain high air leak resistance because the position of the strand does not change and the cross-sectional shape is stable in the circumferential direction.
又撚り方向或いは撚りピッチの少なくとも一方を相違させた通常の層撚り構造を採用した場合には、コア部とシース部とが区分されるため、コア部内にシース素線が落ち込むスペースが形成される。そのため、ワイヤ断面形状が変化する向きの変形が生じやすくなり、リムとの嵌合力が減じるなど操縦安定性に悪影響を与える。これに対して、本実施形態の撚り構造では、束撚り構造と同様、コンパクトな素線配列となり前記スペースの形成が少なくなるため、リムとの嵌合力を高めて操縦安定性を維持することができる。
In addition, when a normal layer twist structure in which at least one of the twist direction or the twist pitch is different is adopted, the core portion and the sheath portion are separated, so that a space for the sheath wire to fall in the core portion is formed. . For this reason, deformation in the direction in which the wire cross-sectional shape changes is liable to occur, and the steering stability is adversely affected, for example, the fitting force with the rim is reduced. On the other hand, in the twisted structure of the present embodiment, as in the bundle-twisted structure, it becomes a compact strand arrangement and the formation of the space is reduced, so that it is possible to increase the fitting force with the rim and maintain steering stability. it can.
又本実施形態の撚り構造では、束撚り構造と同様、コンパクトな素線配列となるため、ワイヤ内へのゴム浸透性に劣る傾向にある。しかし本実施形態では、前記コア素線11c及び/又はシース素線11sに、図4に示すように、撚り合わされる前の状態で螺旋状又は波形状に型付けされた型付け素線14を含ませている。このように、型付け素線14を含ますことにより、ワイヤ内のゴム浸透性を高めることができ、錆の発生を抑えてビードワイヤの耐久性、ひいてはタイヤの耐久性を向上することができる。なお束撚り構造において型付け素線を用いた場合にも、ある程度ゴム浸透性を高めることができるものの、束撚り構造の場合には、素線の位置がランダムに入れ替わるため型付け素線による隙間の形成も不安定であり、ゴム浸透性が低くなる。これに対して前記撚り構造の場合には、素線の位置が入れ替わらないため隙間が安定して形成されるなど、束撚り構造に比してゴム浸透性への向上効果は高くなる。
Moreover, since the strand structure of this embodiment becomes a compact strand arrangement like the bundle twist structure, it tends to be inferior in rubber permeability into the wire. However, in the present embodiment, the core strand 11c and / or the sheath strand 11s include a typed strand 14 which is typed in a spiral or wave shape before being twisted together as shown in FIG. ing. Thus, by including the embossing element wire 14, the rubber permeability in the wire can be increased, the occurrence of rust can be suppressed, and the durability of the bead wire and thus the durability of the tire can be improved. In addition, even when using a typed strand in a bundle-twisted structure, the rubber permeability can be improved to some extent, but in the case of a bundle-twisted structure, the position of the strand is randomly changed, so a gap is formed by the typed strand. Is also unstable and the rubber permeability is low. On the other hand, in the case of the twisted structure, the effect of improving the rubber permeability is higher than that of the bundle twisted structure, for example, the gaps are stably formed because the positions of the strands are not interchanged.
このように前記ビードワイヤ5aは、リムとの嵌合力を高めて操縦安定性を維持しうるという束撚り構造の利点を発揮しながら、耐エアーリーク性、ゴム浸透性に劣るという束撚り構造が有する欠点を補うことができ、中子工法で形成される空気入りタイヤにおいて、カーカスプライの吹き抜け性、リムとの嵌合力、耐エアーリーク性、及びゴム浸透性の低下を招くことなく、リム組時のビード変形を抑えることができる。
In this way, the bead wire 5a has a bundle twist structure that is inferior in air leak resistance and rubber permeability while exhibiting the advantage of the bundle twist structure that can increase the fitting force with the rim and maintain the steering stability. In the pneumatic tire formed by the core method, which can compensate for the shortcomings, without causing the carcass ply blowout, fitting strength with the rim, air leak resistance, and rubber penetration to deteriorate, Bead deformation can be suppressed.
なお前記型付け素線14における型付けの大きさK(図4に示す。)は、0.02~0.25mmの範囲が好ましく、0.02mmを下回るとゴム浸透性が不充分となり、逆に0.25mmを越えると寸法安定性が低下し、リムとの嵌合力、耐エアーリーク性に悪影響を与える恐れを招く。
The mold size K (shown in FIG. 4) of the mold element wire 14 is preferably in the range of 0.02 to 0.25 mm, and if it is less than 0.02 mm, the rubber permeability is insufficient, and conversely 0 If it exceeds .25 mm, the dimensional stability is lowered, which may adversely affect the fitting force with the rim and the air leak resistance.
前記素線11の線径は、特に規制されないが、ビードワイヤの要求強度の観点から乗用車用タイヤの場合、0.175~0.45mmの範囲が好ましく採用される。又コア素線11cの本数、シース素線11sの本数も、特に規制されないが、ビードワイヤの要求強度の観点から乗用車用タイヤの場合、コア素線11cの本数は2~5本の範囲、シース素線11sの本数はそれより大かつ3~12本の範囲が好ましい。
The wire diameter of the wire 11 is not particularly limited, but in the case of a passenger car tire, a range of 0.175 to 0.45 mm is preferably employed from the viewpoint of the required strength of the bead wire. The number of core strands 11c and the number of sheath strands 11s are not particularly limited, but in the case of a tire for passenger cars, the number of core strands 11c ranges from 2 to 5 in the case of tires for passenger cars. The number of lines 11s is larger than that and is preferably in the range of 3 to 12.
又前記ビードワイヤ5aでは、前記コンパクトな素線配列を実現するため、図5に概念的に示すように、コア素線11cを撚り合わせてコア部12を形成した後、このコア部12の周囲にシース素線11sを巻き付けることが好ましい。なお図中の符号20は、コア素線11cが通るガイド孔20aを中心線回りに設けた第1の撚り合わせダイであり、この第1の撚り合わせダイ20を中心線回りで回転させることにより、コア素線11cを撚り合わせてコア部12を形成する。又符号21は、シース素線11sが通るガイド孔21aを中心線回りに設けた第2の撚り合わせダイであり、この第2の撚り合わせダイ21の中心には前記コア部12が遊挿する遊挿孔21bが開口する。そして、この第1の撚り合わせダイ21を中心線回りで回転させることにより、コア部12の周囲にシース素線11sを巻き付けてシース部13を形成する。なおQsは、シース素線11sの集束位置であって、コア素線11cの集束位置Qcよりも下流側に位置している。そして、第1、第2の撚り合わせダイ20、21の回転数を調整することにより、撚りピッチPc、Psが等しいビードワイヤ5aを形成することができる。又集束位置Qc、Qsが相違するため、コア素線11cとシース素線11s間の位置替えをより確実に防止したビードワイヤ5aをうることが可能となる。
In the bead wire 5a, in order to realize the compact strand arrangement, as shown conceptually in FIG. 5, the core portion 11c is twisted to form the core portion 12, and then the core portion 12 is surrounded by the core wire 12a. It is preferable to wind the sheath wire 11s. In addition, the code | symbol 20 in a figure is the 1st twisting die which provided the guide hole 20a through which the core strand 11c passes around the centerline, and by rotating this 1st twisting die 20 around the centerline The core portion 12 is formed by twisting the core strands 11c. Reference numeral 21 denotes a second twisting die provided around the center line with a guide hole 21a through which the sheath wire 11s passes. The core portion 12 is loosely inserted into the center of the second twisting die 21. The loose insertion hole 21b opens. Then, by rotating the first twisting die 21 around the center line, the sheath wire 11 s is wound around the core portion 12 to form the sheath portion 13. Qs is a converging position of the sheath wire 11s and is located downstream of the converging position Qc of the core wire 11c. And the bead wire 5a with equal twist pitch Pc and Ps can be formed by adjusting the rotation speed of the 1st, 2nd twisting die | dye 20,21. Further, since the converging positions Qc and Qs are different, it is possible to obtain the bead wire 5a in which the position change between the core strand 11c and the sheath strand 11s is more reliably prevented.
次に、前記空気入りタイヤ1の製造方法を説明する。この製造方法は、図6に略示するように、前記空気入りタイヤ1の内腔面を形成するタイヤ形成面30sを外表面に設けた剛性中子30を用い、前記タイヤ形成面30s上に、未加硫のタイヤ構成部材を順次貼り付けることにより生タイヤ1Nを形成する生タイヤ形成工程S1と、この生タイヤ1Nを前記剛性中子30ごと加硫金型内に投入して加硫成形する加硫工程(図示しない。)とを含んで構成される。
Next, a method for manufacturing the pneumatic tire 1 will be described. As schematically shown in FIG. 6, this manufacturing method uses a rigid core 30 provided on the outer surface with a tire forming surface 30s that forms a lumen surface of the pneumatic tire 1, and on the tire forming surface 30s. The raw tire forming step S1 for forming the raw tire 1N by sequentially pasting the unvulcanized tire constituent members, and the raw tire 1N together with the rigid core 30 are put into the vulcanizing mold and vulcanized. And a vulcanizing step (not shown).
前記生タイヤ形成工程S1では、図7(A)~(C)に示すように、
(ア)前記タイヤ形成面30s上で、未加硫のゴムで被覆されたゴム引きのビードワイヤ5aを半径方向内側から外側に渦巻き状に巻き重ねて貼り付けて内のコア片5iを形成する第1のコア片工程S1aと、
(イ)前記内のコア片5iのタイヤ軸方向外側にカーカスプライ6Aの半径方向内端部6AEを巻き下ろして貼付けるステップS1b1を有するカーカス形成工程S1bと、
(ウ)前記カーカスプライ6Aの半径方向内端部6AEのタイヤ軸方向外側に、前記ゴム引きのビードワイヤ5aを半径方向内側から外側に渦巻き状に巻き重ねて貼り付けて外のコア片5oを形成する第2のコア片工程S1cと、
を含む。 In the green tire forming step S1, as shown in FIGS. 7 (A) to (C),
(A) On thetire forming surface 30s, the rubber cored bead wire 5a covered with unvulcanized rubber is spirally wound from the inner side to the outer side in the radial direction and attached to form the inner core piece 5i. 1 core piece process S1a,
(A) a carcass forming step S1b having a step S1b1 of unwinding and attaching the radial inner end 6AE of thecarcass ply 6A to the outer side in the tire axial direction of the inner core piece 5i;
(C) Therubberized bead wire 5a is spirally wound from the radially inner side to the outer side on the outer side in the tire axial direction of the radially inner end 6AE of the carcass ply 6A to form an outer core piece 5o. Second core piece step S1c to perform,
including.
(ア)前記タイヤ形成面30s上で、未加硫のゴムで被覆されたゴム引きのビードワイヤ5aを半径方向内側から外側に渦巻き状に巻き重ねて貼り付けて内のコア片5iを形成する第1のコア片工程S1aと、
(イ)前記内のコア片5iのタイヤ軸方向外側にカーカスプライ6Aの半径方向内端部6AEを巻き下ろして貼付けるステップS1b1を有するカーカス形成工程S1bと、
(ウ)前記カーカスプライ6Aの半径方向内端部6AEのタイヤ軸方向外側に、前記ゴム引きのビードワイヤ5aを半径方向内側から外側に渦巻き状に巻き重ねて貼り付けて外のコア片5oを形成する第2のコア片工程S1cと、
を含む。 In the green tire forming step S1, as shown in FIGS. 7 (A) to (C),
(A) On the
(A) a carcass forming step S1b having a step S1b1 of unwinding and attaching the radial inner end 6AE of the
(C) The
including.
そして、前記ビードワイヤ5aには、前述した如く、コア素線11cの撚り方向及び撚りピッチPcを、シース素線11sの撚り方向及び撚りピッチPsと同一とした前記撚り構造のものが用いられる。
And, as described above, the bead wire 5a has the twist structure in which the twist direction and the twist pitch Pc of the core wire 11c are the same as the twist direction and the twist pitch Ps of the sheath wire 11s.
以上、本発明の特に好ましい実施形態について詳述したが、本発明は図示の実施形態に限定されることなく、種々の態様に変形して実施しうる。
As mentioned above, although especially preferable embodiment of this invention was explained in full detail, this invention is not limited to embodiment of illustration, It can deform | transform and implement in a various aspect.
本発明の効果を確認すべく、表1の仕様のビードワイヤを用い、図1に示す構造の空気入りタイヤ(195/65R15)を、中子工法を用いて作成した。そして、各試供タイヤについて、リム組み時におけるビードコアの変形性、ビードコアの耐エアリーク性、ビードワイヤの耐腐食性、操縦安定性についてテストし、その結果を比較した。なお従来例では、ビードワイヤとして単線ワイヤを使用している。又型付け素線を設ける場合、シース部に使用している。又コア素線の撚り方向とシース素線の撚り方向とは、比較例、実施例ともに同方向としている。
In order to confirm the effect of the present invention, a pneumatic tire (195 / 65R15) having a structure shown in FIG. Each sample tire was tested for bead core deformability, bead core air leak resistance, bead wire corrosion resistance, and steering stability when assembling rims, and the results were compared. In the conventional example, a single wire is used as the bead wire. In addition, when the embedding wire is provided, it is used for the sheath portion. The twist direction of the core wire and the twist direction of the sheath wire are the same in both the comparative example and the example.
表1では、m本の素線を束撚りしたものを1×m構造、m本のコア素線とn本のシース素線とで層撚りしたものをm+n構造、前記m本のコア素線とn本のシース素線とを撚り方向、撚りピッチ同一で撚り合わせた本実施形態の撚り構造をm/n構造として記載している。
In Table 1, a bundle of m strands is a 1 × m structure, a layer twist of m core strands and n sheath strands is an m + n structure, and the m core strands The twisted structure of the present embodiment, in which the twisted wire and the n sheath strands are twisted together with the same twisting direction and twist pitch, is described as the m / n structure.
各タイヤとも、表1に示すビードワイヤの仕様以外、実質的に同仕様である。主な共通仕様は、以下の通りである。
<カーカス>
カーカスプライ数:1枚
カーカスコード材料:ポリエステル
カーカスコード角:88°(対タイヤ赤道)
<ベルト層>
ベルトプライ数:2枚
ベルトコード材料:スチール
ベルトコード角:+28°、-28゜(対タイヤ赤道)
<ビードコア>
内のコア片におけるビードワイヤの巻回数Ni:8
外のコア片におけるビードワイヤの巻回数No:11
ビードエーペックスゴムのゴム硬度:80度(デュロメータA硬さ) Each tire has substantially the same specifications except for the bead wire specifications shown in Table 1. The main common specifications are as follows.
<Carcass>
Number of carcass plies: 1 Carcass cord material: Polyester Carcass cord angle: 88 ° (against tire equator)
<Belt layer>
Number of belt plies: 2 Belt cord material: Steel Belt cord angle: + 28 °, -28 ° (against tire equator)
<Bead core>
Number of windings of bead wire in inner core piece Ni: 8
Number of windings of bead wire in outer core piece No: 11
Rubber hardness of bead apex rubber: 80 degrees (durometer A hardness)
<カーカス>
カーカスプライ数:1枚
カーカスコード材料:ポリエステル
カーカスコード角:88°(対タイヤ赤道)
<ベルト層>
ベルトプライ数:2枚
ベルトコード材料:スチール
ベルトコード角:+28°、-28゜(対タイヤ赤道)
<ビードコア>
内のコア片におけるビードワイヤの巻回数Ni:8
外のコア片におけるビードワイヤの巻回数No:11
ビードエーペックスゴムのゴム硬度:80度(デュロメータA硬さ) Each tire has substantially the same specifications except for the bead wire specifications shown in Table 1. The main common specifications are as follows.
<Carcass>
Number of carcass plies: 1 Carcass cord material: Polyester Carcass cord angle: 88 ° (against tire equator)
<Belt layer>
Number of belt plies: 2 Belt cord material: Steel Belt cord angle: + 28 °, -28 ° (against tire equator)
<Bead core>
Number of windings of bead wire in inner core piece Ni: 8
Number of windings of bead wire in outer core piece No: 11
Rubber hardness of bead apex rubber: 80 degrees (durometer A hardness)
<コード強力>
「JIS G3510の「スチールタイヤコード試験方法」に規定された引張り試験に基づき、コードが破断に至るまでの最大引張り荷重を測定した。つかみの間隔は700mm、引っ張り速度は50mm/minである。」
<曲げ剛性>
「TABER社(米国)製のV-5剛性試験機150-D型を用い、固定端から5cm長さでのびるコードの先端に力を付加し、先端の開き角度θが15°になったときの曲げモーメントの値(gf・cm)として定義する。」
<撚り溜まり>
コードをゴム引きする際に、素線の浮きが発生するかどうかを、目視によって評価した。 <Strong code>
Based on the tensile test defined in “JIS G3510“ Steel Tire Cord Test Method ”, the maximum tensile load until the cord breaks was measured. The distance between the grips is 700 mm, and the pulling speed is 50 mm / min. "
<Bending rigidity>
“When a force is applied to the tip of the cord extending 5 cm from the fixed end using the V-5 stiffness tester 150-D manufactured by TABER (USA), and the opening angle θ of the tip becomes 15 ° It is defined as the value of the bending moment (gf · cm).
<Twist pool>
Whether the wire floats or not when the cord is rubberized was visually evaluated.
「JIS G3510の「スチールタイヤコード試験方法」に規定された引張り試験に基づき、コードが破断に至るまでの最大引張り荷重を測定した。つかみの間隔は700mm、引っ張り速度は50mm/minである。」
<曲げ剛性>
「TABER社(米国)製のV-5剛性試験機150-D型を用い、固定端から5cm長さでのびるコードの先端に力を付加し、先端の開き角度θが15°になったときの曲げモーメントの値(gf・cm)として定義する。」
<撚り溜まり>
コードをゴム引きする際に、素線の浮きが発生するかどうかを、目視によって評価した。 <Strong code>
Based on the tensile test defined in “JIS G3510“ Steel Tire Cord Test Method ”, the maximum tensile load until the cord breaks was measured. The distance between the grips is 700 mm, and the pulling speed is 50 mm / min. "
<Bending rigidity>
“When a force is applied to the tip of the cord extending 5 cm from the fixed end using the V-5 stiffness tester 150-D manufactured by TABER (USA), and the opening angle θ of the tip becomes 15 ° It is defined as the value of the bending moment (gf · cm).
<Twist pool>
Whether the wire floats or not when the cord is rubberized was visually evaluated.
(1)ビードコアの変形性:
市販のタイヤチェンジャを用いてリムからタイヤを取り外すとともに、その時、レバーによって最も捻られたビードコアにおける変形が、タイヤ取り外し後も回復しないで残存しているかどうかを目視によって検査した。 (1) Deformability of bead core:
The tire was removed from the rim using a commercially available tire changer, and at that time, it was visually inspected whether the deformation in the bead core most twisted by the lever remained without being recovered after the tire was removed.
市販のタイヤチェンジャを用いてリムからタイヤを取り外すとともに、その時、レバーによって最も捻られたビードコアにおける変形が、タイヤ取り外し後も回復しないで残存しているかどうかを目視によって検査した。 (1) Deformability of bead core:
The tire was removed from the rim using a commercially available tire changer, and at that time, it was visually inspected whether the deformation in the bead core most twisted by the lever remained without being recovered after the tire was removed.
(2)ビードコアの耐エアリーク性:
タイヤをリム(15×6JJ)に装着し、かつ内圧を200kPaを充填して、30日間自然放置したときの内圧低下率を従来タイヤを100とする指数で表示している。値が大きいほど耐エアリーク性に優れている。 (2) Air leak resistance of the bead core:
The rate of decrease in internal pressure when the tire is mounted on a rim (15 × 6 JJ) and filled with 200 kPa of internal pressure and left to stand for 30 days is indicated by an index with the conventional tire as 100. The larger the value, the better the air leak resistance.
タイヤをリム(15×6JJ)に装着し、かつ内圧を200kPaを充填して、30日間自然放置したときの内圧低下率を従来タイヤを100とする指数で表示している。値が大きいほど耐エアリーク性に優れている。 (2) Air leak resistance of the bead core:
The rate of decrease in internal pressure when the tire is mounted on a rim (15 × 6 JJ) and filled with 200 kPa of internal pressure and left to stand for 30 days is indicated by an index with the conventional tire as 100. The larger the value, the better the air leak resistance.
(3)ビードワイヤの耐腐食性:
温度70℃、相対湿度95%の湿熱オーブン内でタイヤを21日間放置した後、ドラム走行試験機を用いて耐久テストを行った。耐久テストは、タイヤ内圧190kPa、荷重6.96kNの速度80km/Hの条件下で375時間連続走行した。そして走行後にタイヤを解体し、ビードワイヤにおける錆の発生状況を、5点法にて評価した。値が大なほど耐腐食性に優れている。 (3) Corrosion resistance of bead wire:
After the tire was left for 21 days in a humid heat oven at a temperature of 70 ° C. and a relative humidity of 95%, a durability test was performed using a drum running tester. In the durability test, the vehicle ran continuously for 375 hours under conditions of a tire internal pressure of 190 kPa and a load of 6.96 kN at a speed of 80 km / H. And the tire was disassembled after driving | running | working and the generation | occurrence | production condition of the rust in a bead wire was evaluated by the 5-point method. The larger the value, the better the corrosion resistance.
温度70℃、相対湿度95%の湿熱オーブン内でタイヤを21日間放置した後、ドラム走行試験機を用いて耐久テストを行った。耐久テストは、タイヤ内圧190kPa、荷重6.96kNの速度80km/Hの条件下で375時間連続走行した。そして走行後にタイヤを解体し、ビードワイヤにおける錆の発生状況を、5点法にて評価した。値が大なほど耐腐食性に優れている。 (3) Corrosion resistance of bead wire:
After the tire was left for 21 days in a humid heat oven at a temperature of 70 ° C. and a relative humidity of 95%, a durability test was performed using a drum running tester. In the durability test, the vehicle ran continuously for 375 hours under conditions of a tire internal pressure of 190 kPa and a load of 6.96 kN at a speed of 80 km / H. And the tire was disassembled after driving | running | working and the generation | occurrence | production condition of the rust in a bead wire was evaluated by the 5-point method. The larger the value, the better the corrosion resistance.
(4)操縦安定性:
タイヤをリム(15×6JJ)、内圧(200kPa)の条件下で車両(2000cc)の全輪に装着して、乾燥舗装道路のテストコースを実車走行し、直進性、旋回時の安定性、制動時の車両の挙動などを総合的にプロドライバーによる官能評価によって判定した。評価は、従来タイヤを100とする指数で表示している。値が大きいほど操縦安定性に優れている。 (4) Steering stability:
Tires are mounted on all wheels of a vehicle (2000cc) under conditions of rim (15x6JJ) and internal pressure (200 kPa), run on a test track on a dry paved road, drive straight, stability during turning, braking The behavior of the vehicle at the time was comprehensively judged by sensory evaluation by a professional driver. The evaluation is indicated by an index with the conventional tire as 100. The larger the value, the better the steering stability.
タイヤをリム(15×6JJ)、内圧(200kPa)の条件下で車両(2000cc)の全輪に装着して、乾燥舗装道路のテストコースを実車走行し、直進性、旋回時の安定性、制動時の車両の挙動などを総合的にプロドライバーによる官能評価によって判定した。評価は、従来タイヤを100とする指数で表示している。値が大きいほど操縦安定性に優れている。 (4) Steering stability:
Tires are mounted on all wheels of a vehicle (2000cc) under conditions of rim (15x6JJ) and internal pressure (200 kPa), run on a test track on a dry paved road, drive straight, stability during turning, braking The behavior of the vehicle at the time was comprehensively judged by sensory evaluation by a professional driver. The evaluation is indicated by an index with the conventional tire as 100. The larger the value, the better the steering stability.
表の如く実施例のコードは、リムとの嵌合力、耐エアーリーク性、ゴム浸透性の低下を招くことなく、リム組時のビード変形を抑えうるのが確認しうる。
As shown in the table, it can be confirmed that the cords of the examples can suppress the bead deformation at the time of assembling the rim without causing a decrease in fitting force with the rim, air leak resistance, and rubber permeability.
2 トレッド部
3 サイドウォール部
4 ビード部
5 ビードコア
5a ビードワイヤ
5i 内のコア片
5o 外のコア片
6 カーカス
6A カーカスプライ
11 素線
11c コア素線
11s シース素線
12 コア部
13 シース部
14 型付け素線
S1 生タイヤ形成工程
S1a 第1のコア片工程
S1b カーカス形成工程
S1c 第2のコア片工程 2tread portion 3 side wall portion 4 bead portion 5 bead core 5a core piece 5o inside bead wire 5i outer core piece 6 carcass 6A carcass ply 11 strand 11c core strand 11s sheath strand 12 core portion 13 sheath portion 14 S1 Raw tire forming step S1a First core piece step S1b Carcass forming step S1c Second core piece step
3 サイドウォール部
4 ビード部
5 ビードコア
5a ビードワイヤ
5i 内のコア片
5o 外のコア片
6 カーカス
6A カーカスプライ
11 素線
11c コア素線
11s シース素線
12 コア部
13 シース部
14 型付け素線
S1 生タイヤ形成工程
S1a 第1のコア片工程
S1b カーカス形成工程
S1c 第2のコア片工程 2
Claims (4)
- トレッド部からサイドウォール部をへてビード部のビードコアに至るカーカスプライからなるカーカスを具える空気入りタイヤであって、
前記ビードコアは、タイヤ軸方向内外のコア片からなり、かつ前記カーカスプライの半径方向内端部が、ビードコアの廻りで折り返されることなく前記内外のコア片間で狭持されるとともに、
前記内外のビード片は、線径同一の複数本のスチール製の素線を撚り合わせたビードワイヤを、半径方向内側から外側にリムフランジの半径方向外端を越えた高さ位置まで渦巻き状に巻き重ねた渦巻き体からなり、
しかも前記ビードワイヤは、2本以上のコア素線を撚り合わせたコア部と、3本以上のシース素線を前記コア部の回りで撚り合わせたシース部とからなり、かつ前記コア素線及び/又はシース素線は、撚り合わされる前の状態で螺旋状又は波形状に型付けされた型付け素線を含むとともに、
前記コア素線の撚り方向及び撚りピッチPcを、前記シース素線の撚り方向及び撚りピッチPsと同一としたことを特徴とする空気入りタイヤ。 A pneumatic tire comprising a carcass made of a carcass ply extending from a tread portion through a sidewall portion to a bead core of a bead portion,
The bead core is composed of inner and outer core pieces in the tire axial direction, and the radially inner end portion of the carcass ply is sandwiched between the inner and outer core pieces without being folded around the bead core,
The inner and outer bead pieces are formed by spirally winding a bead wire formed by twisting a plurality of steel strands having the same wire diameter from the inside in the radial direction to the outside to the height position beyond the radially outer end of the rim flange. Consisting of stacked spiral bodies,
In addition, the bead wire includes a core portion obtained by twisting two or more core strands and a sheath portion obtained by twisting three or more sheath strands around the core portion, and the core strand and / or Alternatively, the sheath wire includes a shaped wire that is shaped in a spiral or wave shape before being twisted, and
A pneumatic tire characterized in that the twist direction and twist pitch Pc of the core wire are the same as the twist direction and twist pitch Ps of the sheath wire. - 前記ビードワイヤは、前記コア素線が撚り合わされた後、コア部の周囲にシース素線が巻き付けられることを特徴とする請求項1記載の空気入りタイヤ。 The pneumatic tire according to claim 1, wherein the bead wire has a sheath wire wound around a core portion after the core wire is twisted together.
- トレッド部からサイドウォール部をへてビード部のビードコアに至るカーカスプライからなるカーカスを具える空気入りタイヤの製造方法であって、
外表面に空気入りタイヤの内腔面を形成するタイヤ形成面を設けた剛性中子を用い、前記タイヤ形成面上に、ビードコアとカーカスプライとを含む未加硫のタイヤ構成部材を順次貼り付けることにより生タイヤを形成する生タイヤ形成工程を具えるとともに、
この生タイヤ形成工程は、前記タイヤ形成面上で、未加硫のゴムで被覆されたゴム引きのビードワイヤを半径方向内側から外側に渦巻き状に巻き重ねて貼り付けて内のコア片を形成する第1のコア片工程と、
前記内のコア片のタイヤ軸方向外側にカーカスプライの半径方向内端部を貼付けるステップを有するカーカス形成工程と、
前記カーカスプライの半径方向内端部のタイヤ軸方向外側に、前記ゴム引きのビードワイヤを半径方向内側から外側に渦巻き状に巻き重ねて貼り付けて外のコア片を形成する第2のコア片工程とを含み、
しかも前記ビードワイヤは、2本以上のコア素線を撚り合わせたコア部と、3本以上のシース素線を前記コア部の回りで撚り合わせたシース部とからなり、
かつ前記コア素線及び/又はシース素線は、撚り合わされる前の状態で螺旋状又は波形状に型付けされた型付け素線を含むとともに、
前記コア素線の撚り方向及び撚りピッチPcを、前記シース素線の撚り方向及び撚りピッチPsと同一としたことを特徴とする空気入りタイヤの製造方法。 A method for producing a pneumatic tire comprising a carcass made of a carcass ply extending from a tread portion through a sidewall portion to a bead core of a bead portion,
Using a rigid core provided with a tire forming surface that forms the inner cavity surface of a pneumatic tire on the outer surface, unvulcanized tire components including a bead core and a carcass ply are sequentially pasted on the tire forming surface. In addition to providing a raw tire forming process to form a raw tire by
In the green tire forming step, a rubber-coated bead wire coated with unvulcanized rubber is spirally wound from the inside in the radial direction to the outside on the tire forming surface to form an inner core piece. A first core piece process;
A carcass forming step having a step of sticking a radially inner end portion of the carcass ply to the outer side in the tire axial direction of the inner core piece;
A second core piece step of forming an outer core piece by winding and sticking the rubberized bead wire on the outer side in the tire axial direction of the radially inner end of the carcass ply in a spiral shape from the inner side to the outer side in the radial direction Including
Moreover, the bead wire includes a core portion obtained by twisting two or more core strands and a sheath portion obtained by twisting three or more sheath strands around the core portion,
And the said core strand and / or a sheath strand include the type | molding strand shape | molded by the spiral or the wave shape in the state before being twisted together,
The manufacturing method of the pneumatic tire characterized by making the twist direction and twist pitch Pc of the said core strand the same with the twist direction and twist pitch Ps of the said sheath strand. - 前記ビードワイヤは、前記コア素線が撚り合わされた後、コア部の周囲にシース素線が巻き付けられることを特徴とする請求項3記載の空気入りタイヤの製造方法。 4. The method of manufacturing a pneumatic tire according to claim 3, wherein the bead wire includes a sheath wire wound around a core portion after the core strand is twisted.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP12768084.1A EP2684712B1 (en) | 2011-04-08 | 2012-01-30 | Pneumatic tire, and method for manufacturing same |
US14/003,538 US20130340910A1 (en) | 2011-04-08 | 2012-01-30 | Pneumatic tire, and method for manufacturing same |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2011086076A JP5144783B2 (en) | 2011-04-08 | 2011-04-08 | Pneumatic tire and manufacturing method thereof |
JP2011-086076 | 2011-04-08 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2012137528A1 true WO2012137528A1 (en) | 2012-10-11 |
Family
ID=46968935
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2012/051998 WO2012137528A1 (en) | 2011-04-08 | 2012-01-30 | Pneumatic tire, and method for manufacturing same |
Country Status (4)
Country | Link |
---|---|
US (1) | US20130340910A1 (en) |
EP (1) | EP2684712B1 (en) |
JP (1) | JP5144783B2 (en) |
WO (1) | WO2012137528A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104768778A (en) * | 2012-11-09 | 2015-07-08 | 住友橡胶工业株式会社 | Pneumatic tire and production method therefor |
JP2017001673A (en) * | 2016-10-12 | 2017-01-05 | 住友ゴム工業株式会社 | Pneumatic tire and manufacturing method thereof |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR3030348B1 (en) * | 2014-12-23 | 2017-06-23 | Michelin & Cie | METHOD FOR ASSEMBLING PNEUMATIC BRAKE |
JP6828390B2 (en) * | 2016-11-16 | 2021-02-10 | 住友ゴム工業株式会社 | Pneumatic tires |
JP6870451B2 (en) * | 2017-04-14 | 2021-05-12 | 横浜ゴム株式会社 | Steel cord and pneumatic radial tire using it |
DE112018004432T5 (en) * | 2017-10-06 | 2020-05-28 | Sumitomo Electric Tochigi Co. Ltd. | STEEL ROPE AND TIRE |
JP7245632B2 (en) * | 2018-10-31 | 2023-03-24 | 株式会社ブリヂストン | tire |
KR102566457B1 (en) * | 2021-07-09 | 2023-08-14 | 금호타이어 주식회사 | The pneumatic tire |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006160236A (en) | 2004-11-11 | 2006-06-22 | Sumitomo Rubber Ind Ltd | Pneumatic tire and its manufacturing method |
JP2007039832A (en) * | 2005-08-02 | 2007-02-15 | Sumitomo Rubber Ind Ltd | Metallic cord for tire, and pneumatic tire using the same |
JP2007191815A (en) * | 2006-01-18 | 2007-08-02 | Tokusen Kogyo Co Ltd | Steel cord and automotive tire |
JP2008297659A (en) * | 2007-05-31 | 2008-12-11 | Yokohama Rubber Co Ltd:The | Steel cord for reinforcing rubber and pneumatic radial tire using the same |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
BR9007652A (en) * | 1989-09-18 | 1992-07-07 | Bekaert Sa Nv | OPEN CABLE STRUCTURE |
JPH0696829B2 (en) * | 1990-05-02 | 1994-11-30 | 住友ゴム工業株式会社 | Pneumatic tire |
JP4603144B2 (en) * | 2000-11-24 | 2010-12-22 | 住友ゴム工業株式会社 | Metal cord for rubber article reinforcement |
FR2870164B1 (en) * | 2004-05-12 | 2006-07-14 | Michelin Soc Tech | PNEUMATIC AND COMPOSITE METAL / RUBBER FOR PNEUMATIC |
PL1841605T3 (en) * | 2005-01-25 | 2009-04-30 | Pirelli | Pneumatic tyre with improved bead structure |
-
2011
- 2011-04-08 JP JP2011086076A patent/JP5144783B2/en active Active
-
2012
- 2012-01-30 WO PCT/JP2012/051998 patent/WO2012137528A1/en active Application Filing
- 2012-01-30 EP EP12768084.1A patent/EP2684712B1/en active Active
- 2012-01-30 US US14/003,538 patent/US20130340910A1/en not_active Abandoned
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006160236A (en) | 2004-11-11 | 2006-06-22 | Sumitomo Rubber Ind Ltd | Pneumatic tire and its manufacturing method |
JP2007039832A (en) * | 2005-08-02 | 2007-02-15 | Sumitomo Rubber Ind Ltd | Metallic cord for tire, and pneumatic tire using the same |
JP2007191815A (en) * | 2006-01-18 | 2007-08-02 | Tokusen Kogyo Co Ltd | Steel cord and automotive tire |
JP2008297659A (en) * | 2007-05-31 | 2008-12-11 | Yokohama Rubber Co Ltd:The | Steel cord for reinforcing rubber and pneumatic radial tire using the same |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104768778A (en) * | 2012-11-09 | 2015-07-08 | 住友橡胶工业株式会社 | Pneumatic tire and production method therefor |
EP2910390A4 (en) * | 2012-11-09 | 2016-05-25 | Sumitomo Rubber Ind | Pneumatic tire and production method therefor |
US10189317B2 (en) | 2012-11-09 | 2019-01-29 | Sumitomo Rubber Industries Ltd. | Pneumatic tire having twisted bead cords |
JP2017001673A (en) * | 2016-10-12 | 2017-01-05 | 住友ゴム工業株式会社 | Pneumatic tire and manufacturing method thereof |
Also Published As
Publication number | Publication date |
---|---|
JP2012218569A (en) | 2012-11-12 |
EP2684712A9 (en) | 2014-06-25 |
US20130340910A1 (en) | 2013-12-26 |
EP2684712B1 (en) | 2018-04-25 |
EP2684712A1 (en) | 2014-01-15 |
JP5144783B2 (en) | 2013-02-13 |
EP2684712A4 (en) | 2014-12-03 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5144783B2 (en) | Pneumatic tire and manufacturing method thereof | |
JP4630096B2 (en) | Motorcycle tires | |
JP4377871B2 (en) | Motorcycle tires | |
WO2013108464A1 (en) | Method for manufacturing pneumatic tire | |
US8590587B2 (en) | Pneumatic tire | |
JP5227392B2 (en) | Pneumatic tire and method for manufacturing pneumatic tire | |
JP2013043548A (en) | Pneumatic radial tire for passenger car | |
WO2004041554A1 (en) | Radial tire with circumferential spirally wound belt layer | |
JP5216067B2 (en) | Pneumatic tire manufacturing method | |
JP6617567B2 (en) | Pneumatic tire | |
JP4553074B1 (en) | Pneumatic tire for passenger car and method for manufacturing pneumatic tire for passenger car | |
JP5104047B2 (en) | Pneumatic radial tire | |
JP5973955B2 (en) | Pneumatic tire | |
WO2014073303A1 (en) | Pneumatic tire and production method therefor | |
WO2015098554A1 (en) | Pneumatic tire | |
JP6247730B2 (en) | Pneumatic tire and manufacturing method thereof | |
JP5013522B2 (en) | Pneumatic radial tire | |
JP4905963B2 (en) | Pneumatic tire | |
JP2012131109A (en) | Method of manufacturing pneumatic tire and bead apex rubber | |
JP2013107518A (en) | Pneumatic tire | |
JP5257411B2 (en) | Pneumatic tire | |
JP4941720B2 (en) | Tire molding method | |
JP5443969B2 (en) | Pneumatic tire | |
JP2011225182A (en) | Pneumatic tire and method of manufacturing the same | |
JP2009137557A (en) | Radial tire |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 12768084 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 14003538 Country of ref document: US |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2012768084 Country of ref document: EP |